A GREEN SUN AND ASSOCIATED PHENOMENA. 397 



19th, 0-40 ; — total, 215 inches. [Average for September, 665 inches on thirteen 

 days.] During the month we had no thunder or lightning. Early in the 

 month the wind was from the north, which was unusual." An examination of 

 the daily weather reports for the month shows that in the earlier part the 

 " general weather " to the north was threatening or overcast, in the central 

 parts of the Presidency it was fine with passing clouds, and in the south sultry. 

 From about the 7th onwards for some days there are frequent reports of " dust 

 haze," " sultry," and " dark gloomy weather " in the reports ; while, on the other 

 hand, at two stations the report is, "atmosphere unusually clear." 



The rainfall for September over the whole Presidency was much less than 

 usual. The average for fifteen stations for which reliable data are available is 

 3 - 24 inches, instead of 6 -90, the average for preceding years. The monsoon 

 rainfall, on the other hand, was much above the average for the same fifteen 

 stations. The rain at some stations continued into January, but taking only 

 the months of October, November, and December, the average rainfall was 

 21 75 inches, while the average due for the same time is 17'36. This includes 

 Bellary, at which the fall was 11 90 inches below the average. 



The barometric variations during the month also seem worth a careful 

 study. Except for Madras, I have only the 10 a.m. readings, but these may 

 generally be taken as yielding a fairly accurate, though rather less smooth, 

 barometric curve than that which would be obtained from the mean of the 

 corrected three daily observations. The accompanying diagram shows the 

 curves for Colombo, Madras, Belgaum, Allahabad, and Calcutta (Alipore). 

 The first point that strikes one on examining the curves is their strong general 

 resemblance, showing the same causes at work in producing change of pressure 

 over the whole area of India. We have first a minimum, which was on the 

 6th at Colombo, Madras, and Allahabad, and on the 7th at Belgaum and Cal- 

 cutta. The delay at these two last places was exceptional, for out of ninety- 

 three stations sending in reports only thirteen show a falling barometer on the 

 7th, and these are connected with small local areas of depression. The rise to 

 a maximum is rather irregular, but it is reached for most stations on the 18th, 

 and the report for the 19th shows a fall at every station except Sholapur and 

 Moulmein. The fall continued till the 21st, when a rise took place at the great 

 majority of stations. A third minimum falls on the 27th. Observations made 

 with the black bulb solar radiation thermometer in vacuo and the grass mini- 

 mum thermometer will be referred to further on. 



In any attempt to discover the cause of the phenomena observed it is of 

 importance to determine exactly the dates at which they were first seen at 

 different places. This, however, is a very difficult thing to do, inasmuch as 

 most of those who have reported on the subject have been untrained in exact 



VOL. XXXII. PART II. 3 S 



